I go with the 3lb rule because it's what I found my builds worked out to pretty consistently. Strats have heavier bridges but Tele's have heavier knobs! I build mostly Esquires though with no tone control so my parts count stays lower than usual. As far as wanting a target light weight, I'd look to a future where you hope to live a while, get old, still have electricity and police etc; thus buy a lighter body that will still please you when you're 64. I just never buy a body over 4lbs any more, but am not yet ready for paulownia!